制做远程缩略图

/// <summary>
        /// 制做远程缩略图
        /// </summary>
        /// <param name="url">图片URL</param>
        /// <param name="newFileName">新图路径</param>
        /// <param name="maxWidth">最大宽度</param>
        /// <param name="maxHeight">最大高度</param>
        public static void MakeRemoteThumbnailImage(string url, string newFileName, int maxWidth, int maxHeight)
        {
            Stream stream = GetRemoteImage(url);
            if(stream == null)
                return;
            Image original = Image.FromStream(stream);
            stream.Close();
            MakeThumbnailImage(original, newFileName, maxWidth, maxHeight);
        }

        /// <summary>
        /// 获取图片流
        /// </summary>
        /// <param name="url">图片URL</param>
        /// <returns></returns>
        private static Stream GetRemoteImage(string url)
        {
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method = "GET";
            request.ContentLength = 0;
            request.Timeout = 20000;
            HttpWebResponse response = null;

            try
            {
                response = (HttpWebResponse)request.GetResponse();
                return response.GetResponseStream();
            }
            catch
            {
                return null;
            }
        }